93 90s with emissions, idle problems

[Kent McLean]

Dan Gessner wrote:
 > Tomorrow, I'll be going to look at a 1993 90s, 5spd, 141k miles
 > that someone's got for sale at $700.  I need some advice on what
 > to look for.

 From what you described, here are a few things...

1. Bring jumper cables with you to get it started and keep it running.

2. You should be able to pull the diagnostic codes (DTCs) from
    the engine, to get a handle on its problems. See:
    <http://www.12v.org/maintenance/dtc.php>

    Note that the web site description matches the connections as
    pictured. On my '94 100 S Avant, the connections were turned,
    so I had to adjust accordingly.  Look at the picture closely,
    and you should see which terminals to probe.

3. The O2 sensors can cause idling problems, as the erratic behavior
    causes varying (and bad) fuel adjustments. They should show up
    in the DTCs.
    See: <http://www.12v.org/maintenance/repairs/o2sens.php>

4. The coolant leak could be brittle plastic cracking and causing
    a leak. IIRC, the radiator has plastic end caps, and the overflow
    tank is plastic. Or maybe an old hose. Worst case is a leaking
    heater core inside the dash.  For that last one, you might smell
    the antifreeze inside the car.

5. The "using" oil may be just a leak. The valley gasket is a
    known leaker, as are valve cover gaskets and some o-rings.
    Check the archives.

    The 1/2-1 qt oil used per month, at 1000 miles/mo average,
    may not be too bad.  My rule of thumb (learned long ago and
    maybe not applicable to newer cars) is 3000 miles per quart,
    or 1 qt between oil changes.  I'm sure readers will chime in
    with 5000 miles per quart. 1/2 quart per 1000 miles is 1 qt
    per 2000 miles, and isn't too bad. But 1 quart every 1000
    miles would be an issue.

    Since the car hasn't run since 2003, and the owner rates
    the loss as monthly rather than as mileage, I'd guess the
    loss is from leakage rather than usage.

HTH.

--
Kent McLean
'94 100 S Avant, "Moody"
'89 200 TQ, "Bad Puppy" up in smoke


    you would see